1. Field of the Invention
The present invention relates to,a nozzle plate member (also referred to as a gas diffusion plate) for supplying fluids in a dispersed manner, and a manufacturing method thereof. More specifically, the invention relates to a film-forming nozzle plate member for dispersing and causing gas to feed and flow out, the gas being used for a film-forming process in manufacturing a semiconductor device or a liquid crystal substrate device, and a manufacturing method of such a nozzle plate member.
2. Description of the Related Art
In the process of manufacturing a semiconductor device or a liquid crystal display substrate, film formation has been carried out by spaying gas to a substrate in the process of chemical vapor deposition (CVD) or the like. In such a film-forming process, each of gases of one, two or more kinds, selected from silane gas, oxygen gas, and so on, is supplied, a plurality of gases are uniformly mixed immediately before the substrate, and then a film is formed on the substrate. In the film-forming process, the dispersed supplying of the plurality of gases must be maintained separately immediately before the gases are reached on the substrate, and each of the gases must be supplied to keep uniform mixing on a substrate surface.
Thus, the inventors examined a conventional nozzle plate like that shown in each of FIGS. 26(a) and 26(b), which was used to disperse gases as fluids in stages and supply them through a number of holes. FIG. 26(a) is a sectional view of a gas supplying nozzle plate, and FIG. 26(b) is a sectional view.
As shown in FIGS. 26(a) and 26(b), the gas supplying nozzle plate is constructed by laminating sheet metal members 40, 41 and 42. The plate metal member 40 includes an A gas path hole 43, its branch 44, and a B gas path hole 47, which are all formed by machining. The plate metal member 41 includes an A gas path hole 45, a B gas path hole 48 and its branch 49, which are all formed by machining. The plate metal member 42 includes an A gas path hole 46 and a B gas path hole 50, which are formed by machining. These plate metal members 40, 41 and 42 are joined together by soldering, electron beam welding or bolt fastening, and then laminated to form a unified body.
In the gas supplying nozzle plate constructed by laminating the metal members 40, 41 and 42, A gas is passed through the path hole 43, branched at the branch 44, and dispersed into a number of flows. Then, the A gas flows out through the path holes 45 and 46 to be supplied to a film-forming region. B gas is passed through the path holes 47 and 48, branched at the branch 49, and dispersed into a number of flows. Then, the B gas flows out through the path hole 50 to be supplied to the film-forming region. Then, the A and B gases are mixed with each other immediately before the substrate to form a film on the substrate.
The gas supplying nozzle plate described above with reference to FIGS. 26(a) and 26(b) can supply gas in a dispersed manner. However, problems have been inherent particularly with respect to sealing, the state of the joined portions of the gas path holes, and so on, in the cases of joining by soldering, electron beam welding, and bolt fastening. Specifically, in the case of joining by soldering, the problems include: a reduction in sealing, which is caused by a pinhole formed by gas entrainment during soldering; a loss of cleanness necessary for semiconductor manufacturing or a liquid crystal substrate manufacturing, which is caused by gas generated from a component such as solder; a loss of dimension or function of the gas path hole, which is caused by damaging the precise and fine gas path hole or the branch, such damaging occurring due to the melting of brazing filler metal during joining; and others. To solve the problem of the damaging the gas path hole caused by the melting of solder during joining, soldering foil was used. However, the use of such soldering foil proved to be costly, because the need to process and dispose the soldering foil to match the shape of the precise and fine gas path hole or the branch resulted in much man-hour. In addition, it was impossible to deal with a temperature of about 400xc2x0 C. during film formation. This problem occurred because of a limitation placed by a temperature during the film formation.
In the case of joining by electron beam welding, the problems include: the difficulties of securing sealing corresponding to all of a number of precise and fine gas path holes or branches formed in the sheet metal member, and carrying out joining without any hole clogging; the difficulty of manufacturing a large gas nozzle plate because of a limitation placed by the size of a high vacuum chamber, in which electron beam joining is performed; and high costs.
In the case of joining by bolt fastening designed to secure sealing by disposing a gasket, the problems include: a loss of designing freedom satisfying a request made by a user, which occurs because of the need to provide a space for machining and disposing a gasket to match the shape of the precise and fine gas path hole or the branch; high costs caused by much man-hour; and the difficulty of securing complete sealing by the gasket. In addition, heat resistance is a significant matter, particularly since such film formation is often carried out at a high temperature. In this respect, it was difficult to provide sufficient heat resistance by the method using the gasket.
The present invention is directed to a gas supplying nozzle plate, which is constructed by laminating a plurality of metal members having fluid paths formed therein. It is an object of the invention to provide a fluid nozzle plate member capable of providing high sealing at joined portions, and high reliability without any reductions in the functions of highly precise fluid paths and branches even when used in high vacuum or at a high temperature. It is another object of the invention to provide a manufacturing method of such a fluid nozzle plate member.
(1) In accordance with the present invention, there is provided a nozzle plate member for supplying fluids in a dispersed manner, comprising a plurality of plate-like metal members each having a fluid path and/or a branch and an annular groove or an annular protrusion around the periphery of the surface of the plate-like metal member. In this case, the plurality of plate-like metal members are laminated by inserting the protrusion into the groove, and press forging is executed for junction of the laminated surfaces thereof.
(2) An annular groove is further provided around the fluid path and/or a branch on the surface of one of the surface to be joined of one of the laminated plate-like metal members, an annular protrusion is provided around the fluid on another surface to be placed oppositely to the former, the annular protrusion is inserted into the annular groove, and then press forging is executed for junction.
(3) The fluid path and/or the branch are formed for each kind of fluids, and each kind of fluids is dispersed to flow out. An annular groove and an annular protrusion are provided around the fluid path and/or a branch on a surface and on the opposing surface to be joined of the laminated metal members, the positions of the annular groove and protrusion being defined for each kind of the fluids. The annular protrusion is inserted into the annular groove, and then press forging is executed for junction.
(4) Further annular grooves are respectively provided around the fluid path and/or branch on the opposing positions of the surfaces being joined of the plurality of metal members each having the fluid path and/or the branch. An intermediate metal member for filling each of the annular grooves is inserted and laminated, and then press forging is executed for junction.
(5) The fluid path and/or the branch is formed for each kind of fluids, and annular grooves are respectively provided in positions defined for each kind of the fluids. An intermediate metal member for filling each of the annular grooves is inserted, and then press forging is executed for junction.
(6) The nozzle plate member can be so constructed that the fluid path and/or the branch is formed for each kind of fluids and an annular protrusion is provided through which the fluid path is provided and is extended through an opposing plate-like metal member.
(7) Preferably, each of the metal members is made of one selected from aluminum metal or an aluminum alloy, because it facilitates press forging.
(8) Furthermore, it is preferred that the fluid path and/or the branch formed in the metal member made of one selected from the aluminum metal and the aluminum alloy is subjected beforehand to surface treatment to prevent corrosion. This is because gas for film formation is usually corrosive.
(9) The nozzle plate member for supplying fluids in a dispersed manner is suitably used as a nozzle plate for dispersing and supplying gas for film formation on a semiconductor device or a liquid crystal display device.
(10) In anther embodiment of the invention, there is provided a manufacturing method regarding the foregoing nozzle plate member for supplying fluids in a dispersed manner. This manufacturing method comprises the steps of: preparing a plurality of plate-like metal members each having a fluid path and/or a branch and an annular groove or an annular protrusion on a peripheral surface of the metal member; and laminating the plurality of plate-like metal members by inserting the protrusion into the groove, and joining the laminated surfaces thereof by press forging.
(11) The manufacturing method of a nozzle plate member further comprises steps of: an annular groove is provided around a fluid path and/or a branch on a surface of one of the laminated plate-like metal members, an annular protrusion is provided around a fluid path and/or a branch on an another surface of the metal member placed oppositely to the former, the annular protrusion is inserted into the annular groove, and then press forging is executed for junction.
(12) The manufacturing method of a nozzle plate member further comprises steps of: an annular groove is provided around a fluid path and/or a branch on a surface of one of the laminated plate-like metal members, an annular groove is also provided around a fluid path and/or a branch on another surface of the metal member placed oppositely to the former, an intermediate metal member to fit in the annular grooves is inserted, and then press forging is executed for junction.
(13) In the manufacturing method of a nozzle plate member each of the metal members is preferably made of one selected from aluminum metal and an aluminum alloy.
(14) In the manufacturing method of a nozzle plate member a step is further provided to subject the fluid path and/or the branch formed in the metal member made of one selected from the aluminum metal and the aluminum alloy beforehand to surface treatment to prevent surface corrosion.
(15) In the manufacturing method of the nozzle plate member, the press forging is preferably carried out at a pressure set in the range of 3 to 100 kgf/mm2.
(16) Furthermore, the press forging is preferably carried out at a temperature set in the range of 300 to 500xc2x0 C. It is because press forging of aluminum is easy in this temperature range.